Manufacture of nitrogen compounds of silicon and aluminium.



PATENT OFFICE.

OTTOKAR SERPEK; OF PARIS, FRANCE,

A SSIGNOR T0 S OCIETE GENERALE DES NITRURES, OF PARIS, FRANCE.

MANUFACTURE OF NITROGEN CQIVIPOUNDS OF SILICON AND ALUMINIUM.

1,060,640. we Drawing To all whom it may concern: 1

Be it known that I, O'r'roKA'R SERPEK, 12 Rue Roquepine, Paris, France,chemical have invented certain new and useengineer, ful Improvements inthe Manufacture of Nitrogen Compounds of Silicon and Alu-v minium, ofwhich the following is a full, clear, and exact description.

This invention relates to the manufacture of-nitrogen compounds ofsilicon and aluminium from bauxite, kaolin, clays and in general anybodies] containing silica and alumina in mixture or combination,

The invention consists in heating these bodies mixed with the requisitequantity of carbon in a current of nitrogen containing no'oxygen (freeor combined) first to a temperature not exceeding that at which there isdanger of volatilization of the silica and formation of silicon carbid v(about 1300 to 1500 C.) for-a sufiicient time to cause almost the wholeof the silica to be transformed into nitrid, then in raising thistemperature up to the point at which the formation of aluminium nitrid'is effected rapidly (about 1600 to 1800 C.) as indicated in thespecification of U. S. Patent No. 987 ,408. Ex-

, erience has shownthat the silicon nitrid formed during the first stageof the opera-v tion will not be decomposed at the higher temperaturesemployed in the second stage.

' On the other hand, if higher temperatures ,were employed in the firststage of the prociess, part of the silica would be volatilized,

[and also sllicon carbid would be formed,

which is not in itself convertible into nitrid,

,and particles of silicanot transformed would remain and mterferewiththe reaction. In

the second stage of the heating itsufiices to operate in a current ofnitrogen containing no oxygen either free or combined as carbon dioxid,experience having shown that at these high temperatures the presence ofcarbon monoxid does not afl'ect the reaction. Consequently in this stagethere may be used roducer gas free from oxygen and freed from carbondioxid:

Having thus described my invention, what I claim as'such and desire tosecure by Letters Patent is Copies of this patent may be obtained forfive ce wathington,

. Specification of Letters Patent.

Patented May 6, 1913.

Application filed November 9, 1911. Serial No. 659,413.

.1500 to i600 C. to form silicon nitrid and minium nitrid.

v 2. A process for the manufacture of nitrogen compounds of silicon andaluminium, comprising the mixture with carbon of a body containingsilica and alumina, heating said mixture for a suitablelength of time ina current of nitrogen free from oxygen at a-temperature lower than thevolatilization point of silica, and then heating said mixture ina'current of nitrogen t a temperaturesuflicient for the formation ofaluminium nitrid.

,w 3. A process for the manufacture of nitrogen compounds of silicon andaluminium, comprising the mixture with carbon of abody containing silicaand alumina, heating "saidmix'ture in a current of nitrogen free fromoxygenat atemperature lower than the volatilization-point of silicafor asufiicient time to cause transformation of the -silica intojnitrid, andthen cont uing the treatment at ,a' higher temperat; e to the point ofrapid formation of aluminium nitrid. I

4. A process for the manufacture of nitrogen compounds of silicon andaluminium, comprising the mixture with carbon of a body containingsilica and alumina,heating said mixture for a sufiicient time in a cur.-rent of nitrogen free from oxygen at a temperature not exceeding 1300 to1500 C., and then heating said mixture -in a current of nitrogen at atemperature of about 1600 to 1800 C.

- In testimony whereof I have signed my name to this specification, inthe presence 0 two subscribing witnesses.

OTTOKAR SERPEK.

Witnesses EUGENE LEGRIS,

Liaon PEILLET.

nts each, by addressing the Commissioner of Patents,

rent of nitrogen, first at a temperature below theniat ahighertemperature to form alu-.

